To explore further the chemical characteristics of the 0.17 M-eluted glycoprotein peak of retinoic acid treated skin tumors, by digestion to glycopeptide and further degradation. Using the rapid assay (TCA precipitation and assay of radioactivity), development of a more quantitative method of application of retinoic acid (either subcutaneously, under the tumor, or by stomach tube). Start of a histological-morphological investigation of the correlation of retinoic acid treatment-mucous metaplasia-tumor regression correlated with induction of the 0.17 M-eluted glycoprotein.